Excretory urography with iohexol: evaluation in children

A multicenter clinical study was conducted using iohexol, a second-generation nonionic contrast medium, for excretory urography performed in 130 children. Doses of iohexol (300 mg iodine/ml) ranged between 150 and 660 mgI/kg (0.5 and 2.2 ml/kg). Iohexol was tolerated well, and no significant adverse reactions occurred. Sixty-five iohexol urograms were evaluated to determine the minimum dose for adequate visualization of the kidneys and collecting systems. A dose greater than 300 mgI/kg (1.0 ml/kg) always resulted in a urogram of diagnostic quality, while visualization was insufficient for diagnosis in 10% of studies done with doses of 150-300 mgI/kg (0.5-1.0 ml/kg). Another 65 iohexol urograms were compared in a blinded manner with a similar number of studies performed using iothalamate meglumine at comparable iodine concentration and dose. Visualization of calyces and pelvoinfundibular structures achieved with iohexol was rated better with statistical significance, but there was no difference in visualization of the renal parenchyma or ureters. Use of iohexol in excretory urography may be advantageous in children who are at greatest risk for an adverse reaction to contrast media or in those most likely to benefit from use of a low osmolality contrast agent.     

Light microscopic and ultrastructural localization of GABA-like immunoreactive input to retrogradely labeled sympathetic preganglionic neurons

The organization of gamma-aminobutyric acid-like immunoreactive (GABA-LIR) processes was studied within the sympathetic preganglionic neuropil of male Sprague-Dawley rats and pigeons (Columba livia). Sympathetic preganglionic neurons were retrogradely labeled following horseradish peroxidase (HRP) injections into either the adrenal medulla or superior cervical ganglion in rats or into the avian homologue of the mammalian stellate ganglion (paravertebral ganglion 14) in pigeons. GABA-LIR staining was visualized using peroxidase-antiperoxidase (PAP), avidin-biotin complex (ABC), or post-embedding immunogold methods. The pigeon preganglionic neuropil contained a dense network of GABA-LIR processes with punctate swellings that encircled sympathetic preganglionic perikarya within the principal preganglionic cell column (column of Terni) and the nucleus intercalatus spinalis. GABA-LIR spinal neurons were intermingled among HRP-labeled sympathetic preganglionic neurons within the column of Terni and throughout the zona intermedia. In the rat the density of the GABA-LIR processes within the four thoracic sympathetic preganglionic nuclei was less than that observed in the pigeon. Nevertheless, GABA-LIR profiles distinctively dotted preganglionic perikarya within the nuclei intermediolateralis pars principalis and pars funicularis, nucleus intercalatus spinalis and the central autonomic nucleus. GABA-LIR neurons were rarely observed within the nucleus intermediolateralis pars principalis, but were numerous in the zona intermedia and area X. No GABA-LIR spinal neurons in either vertebrate were retrogradely labeled with HRP. The ultrastructural arrangements of GABA-LIR processes within the sympathetic preganglionic neuropils of pigeons and rats were similar. GABA-LIR boutons formed symmetrical synaptic contacts and contained small round electron-lucent vesicles (50 nm) and one to several larger dense-core vesicles (80 nm). GABA-LIR terminals contacted HRP-labeled sympathetic preganglionic perikarya in all spinal nuclear regions in both vertebrates. More frequently, GABA-LIR boutons synapsed on dendrites. Occasionally, axo-axonic configurations were observed; each time only one of the axonal elements was GABA-LIR. Numerous unmyelinated and some thinly myelinated GABA-LIR axons coursed through the sympathetic preganglionic neuropils of both vertebrates. Synapses between GABA-LIR processes were present within the sympathetic preganglionic neuropil of both vertebrates. GABA-LIR dendrites were contacted by unlabeled terminals (predominantly small spherical vesicles with asymmetric synaptic specializations) and GABA-LIR terminals on GABA-LIR dendrites were similar in appearance to those synapsing on sympathetic preganglionic cell bodies and dendrites.     

Primary retroperitoneal myxoid/round cell liposarcoma is a nonexisting disease: an immunohistochemical and molecular biological analysis

Almost all primary retroperitoneal liposarcomas can be classified as well-/dedifferentiated liposarcoma. Rarely, however, primary retroperitoneal liposarcoma is classified as myxoid/round cell liposarcoma, based on the presence of myxoid areas and vascular crow's feet pattern, which has resulted in a debate on the classification of liposarcoma in the retroperitoneum. Genetically, myxoid/round cell liposarcoma and well-/dedifferentiated liposarcoma are different diseases. Myxoid/round cell liposarcoma is characterized by a translocation causing FUS-CHOP or EWSR1-CHOP fusion, whereas well-/dedifferentiated liposarcoma is characterized by an amplification of the 12q13-15 region, including MDM2 and CDK4 genes. As myxoid/round cell liposarcoma is highly radio- and chemosensitive, differentiation between subtypes is important to optimize treatment. We studied whether primary retroperitoneal liposarcomas diagnosed as myxoid/round cell liposarcoma represent molecularly true myxoid/round cell liposarcoma or are histopathological mimics and represent well-/dedifferentiated liposarcoma. Primary retroperitoneal myxoid/round cell liposarcoma (n=16) were compared to primary extremity myxoid/round cell liposarcoma (n=20). Histopathological and immunohistochemical features were studied. Amplification status of the 12q13-15 region was studied using a multiplex ligation-dependent probe amplification analysis, and FUS-CHOP or EWS-CHOP translocations were studied using RT-PCR. In primary retroperitoneal myxoid/round cell liposarcoma, MDM2 and CDK4 staining was both positive in 12 of 15 cases. In primary extremity myxoid/round cell liposarcoma, MDM2 was negative in 18/20 and CDK4 was negative in all cases. Multiplex ligation-dependent probe amplification showed the amplification of 12q13-15 region in 16/16 primary retroperitoneal myxoid/round cell liposarcomas and in 1/20 primary extremity myxoid/round cell liposarcomas. Translocation was present in all (18/18) primary extremity myxoid/round cell liposarcomas, but absent in all primary retroperitoneal myxoid/round cell liposarcomas. On the basis of immunohistochemical and molecular characteristics, apparent primary retroperitoneal myxoid/round cell liposarcoma can be recognized as well-/dedifferentiated liposarcoma with morphological features mimicking myxoid/round cell liposarcoma. In these cases, treatment should probably be specifically designed as for well-/dedifferentiated liposarcoma. Moreover, finding of myxoid/round cell liposarcoma translocations in a retroperitoneal localization is highly suggestive of metastasis and should prompt search for a primary localization outside the retroperitoneum.     

Contraction force generated by tarsal joint flexion and extension in dogs with golden retriever muscular dystrophy.

Force generated due to torque caused by tarsal joint flexion and extension was measured noninvasively at 3, 4.5, 6, and 12 months of age in dogs with the Duchenne homologue, golden retriever muscular dystrophy (GRMD). Absolute and body-weight-corrected GRMD twitch and tetanic force values were lower than normal at all ages (P<0.01 for most). Tarsal flexion and extension were differentially affected. Flexion values were especially low at 3 months, whereas extension was affected more at later ages. Several other GRMD findings differed from normal. The twitch/tetany ratio was generally lower; post-tetanic potentiation for flexion values was less marked; and extension relaxation and contraction times were longer. The consistency of GRMD values was studied to determine which measurements will be most useful in evaluating treatment outcome. Standard deviation was proportionally greater for GRMD versus normal recordings. More consistent values were seen for tetany versus twitch and for flexion versus extension. Left and right limb tetanic flexion values did not differ in GRMD; extension values were more variable. These results suggest that measurement of tarsal tetanic force should be most useful to document therapeutic benefit in GRMD dogs.     

Eccentric contractions induce rapid isometric torque drop in dystrophin‐deficient dogs

We tested the hypothesis that eccentric contractions (ECCs) rapidly induce greater‐than‐normal isometric torque drop in dystrophin‐deficient golden retriever muscular dystrophy (GRMD) muscles. ECCs were imposed by forcibly stretching activated muscles. The results indicate that isometric torque drop was greater in GRMD versus controls (P < 0.0001). Our findings support the hypothesis that ECCs induce greater‐than‐normal isometric torque drop in GRMD muscles. The magnitude of ECC‐induced isometric torque loss may be an ideal clinical endpoint in the GRMD model. Muscle Nerve, 2010     

A SURVEY OF HOSPITAL MORBIDITY,MORTALITY AND QUALITY OF LIFE FOLLOWING CORONARY ARTERY BYPASS SURGERY IN A UK INDO-ASIAN POPULATION

To survey the in-hospital morbidity, mortality, length of stay in the intensive therapy unit (ITU) and hospital and quality of life in patients of Indo-Asian origin following coronary artery bypass (CABG) surgery, 345 consecutive patients (mean age 58 years; SD 8.9; range 32-88 years) undergoing primary, isolated CABG were studied. Non-elective CABG was undertaken in 41% of patients. The left anterior descending artery (LAD) was grafted in 89%, although in 30% of these the internal mammary artery (IMA) was not used. Following CABG, the hospital morbidity and mortality was within the expected range, although there was a trend towards higher in-hospital mortality in the Parsonnet low risk group of patients. The length of ITU and hospital stay was not prolonged. Using the SF-36 questionnaire in postoperative patients, low quality of life scores were obtained for six of the eight modalities tested including physical functioning, bodily pain and general health perception. The low quality of life scores and IMA usage in Indo-Asians needs to be addressed.